A shifting mechanism of a manual transmission will be described with reference to FIG. 1 to help understanding of the present disclosure.
As shown in FIG. 1, the shifting mechanism of a manual transmission 1 includes a shift lever 4 that disposed directly on a housing 2 of the manual transmission 1 to turn and transmits an operation force applied by a driver. A shift rail 6 is coupled to a lower end of the shift lever 4 and axially moves by operation force of the shift lever 4. A shift fork 10 is fixed to one end of the shift rail 6 and engaged with a sleeve 8 of a synchronizer.
In this configuration, a plurality of shift rails 6 are provided in the manual transmission 1, a shift lug 7 is formed at another end of the shift rail 6. A control finger 5 is engaged with the shift lug 7 and formed at the lower end of the shift lever 4.
According to this structure, the control finger 5 of the shift lever 4 is engaged with the shift lug 7 of any one of the shift rails 6. The shift lug 7 is engaged with the control finger 5 and axially moves by the operation force applied to the shift lever 4.
The shift fork 10 is composed of a fork seat 12 which is fixed to the one end of the shift rail 6, and a fork gripper 14 which is formed on a bottom of the fork seat 12 and grasps the sleeve 8. The one end of the shift rail 6 passes through the fork seat 12, and the fork seat 12 and the shift rail 6 are fixed by fasteners.
The fork gripper 14 has a semicircular shape to be fitted in a sleeve groove 8a formed on the sleeve 8 so that the sleeve 8 can rotate and axially move. A pad member (not shown) is attached to a portion, which comes in contact with an inner side of the sleeve groove 8a, of the fork gripper 14.
According to the shifting mechanism of the manual transmission which as this configuration, as a gear is selected by the shift lever 4, the control finger 5 of the shift lever is engaged with any one of the shift lugs 7, and then as the shift lever 4 is operated to shift, the control finger 5 of the shift lever 4 moves the shift lug 7 in an axial direction of the shift rail 6.
Accordingly, as the shift rail 6 moves by the shift lug 7, the shift fork 10 which is fixed to the shift rail 6 and the sleeve 8 move. As the sleeve 8 moves, a shift gear 16 is synchronized and engaged.
According to a 7-speed manual transmission, as shown in FIG. 2, five shift rails 6 are provided, and particularly, selection positions of an R-gear and a seventh gear are different, but their shifting directions are the same, so it is impossible to implement a gear trail that can shift with one synchro hub and one sleeve.
That is, the synchro hub and the sleeve are required for shifting to the R-gear and the seventh gear, respectively, and thus, manufacturing cost and a length of a gear train are increased.
There are a related art titled “Shift apparatus of manual speed change gear for use in automobile” and a related art titled “Shifting control apparatus for manual transmission.”
In “Shift apparatus of manual speed change gear for use in automobile”, a shift apparatus of a manual transmission for an automobile can shift to other gears in addition to shifting to two gears with one shift rail, but there is no structure of a dual shift fork, and shifting to two gears is performed by a detent structure, such that shifting is complicated. In “Shifting control apparatus for manual transmission”, the volume of a shifting control apparatus is reduced, and components are simplified by connecting a control shaft directly with a shift fork, however, it does not provide implementing gears, in which the selection directions of the gears are different but shifting directions thereof are the same.
The foregoing is intended merely to aid in the understanding of the background of the present disclosure, and is not intended to mean that the present disclosure falls within the purview of the related art that is already known to those skilled in the art.